Chain assembly method for joining a flat link articulated chain

ABSTRACT

The invention relates to a chain assembly method for joining a single or multiple link-plate chain having alternating, uncranked outer and inner chain links using prefabricated inner chain links in particular comprising two parallel link plates and parallel hollow pins connecting the latter. This assembly method is to be simplified as compared with production methods used hitherto for link plate chains.

BACKGROUND OF THE INVENTION

The present invention relates to a chain assembly method for joining alink-plate chain having alternating outer and inner chain links usingprefabricated inner chain links comprising two parallel link plates andparallel hollow pins connecting the latter.

Single or multiple chains, in particular for drive and conveyingpurposes, are normally produced in the manner of a layer constructionmethod. In the case of a single chain, for example, in one methodvariant first of all a lower outer link plate is put in place, then aninner chain link is arranged on this, a link pin is subsequentlyinserted through the aligned holes in these two parts and then the upperouter link is preassembled, after that the upper outer link plate isassembled to dimension and finally the end regions of the link pin areriveted. Each of the steps mentioned above is carried out during oneclock cycle during assembly. Accordingly, six clock cycles are needed toassemble a single chain. In this case, work is carried out against afixed stop and the latter is formed by a guide surface on which theunderside of the lower outer link plate rests. The axes of the link pinsand associated holes in the components are arranged in such a way thatsecure contact with the lower outer link plate is provided by the forceof gravity.

DE 19836374 also discloses an assembly method in which, by means of thesymmetrical execution of a tongs-like movement, joining is not carriedout against a fixed stop but symmetrically in relation to a principalchain center line. Described in detail there is only the joining of theinner chain link, without discussing in more detail the joining orassembly sequence of the chain overall. Also shown in this document is afeed system in the form of a rotary table, which feeds the horizontallyguided link plates and the vertically guided hollow pins toward eachother.

Furthermore, in the case of track chains with cranked chain links, forexample, it is known to join these together in the horizontal direction.In such track chains, such as are produced in accordance with U.S. Pat.No. 4,027,471 in an assembly system, all the chain links are of the sameconstruction, so that no distinction can be drawn between inner andouter chain links. The joining operation is carried out in such a waythat both the hollow pin and the link pin are inserted at the same time.Here, too, during the actual joining operation, work is carried outagainst a fixed stop for one of the cranked link plates. The horizontalarrangement of the link pin axes is probably preferred in the case ofcranked chains, since their cranked-over link plates do not provide anyflat supporting surface.

It is now the object of the present invention to provide a simplifiedchain assembly method for the assembly of single and multiple chainshaving inner and outer chain links.

SUMMARY OF THE INVENTION

According to the invention, this object is achieved by a method havingthe following steps:

providing at least one completely prefabricated inner chain link,

positioning the inner chain link so that the hollow pin axis of the atleast one inner chain link is aligned substantially parallel to thesupporting or retaining face of the inner chain link,

providing at least one link pin,

positioning the at least one link pin so that the pin axis is arrangedcoaxially with the hollow pin axis of the associated hollow pin of aninner chain link,

inserting the link pin into the hollow pin by means of relativedisplacement of the link pin and of the at least one inner chain link inrelation to each other so that the end regions of the link pin projecton both sides,

providing at least one pair of outer link plates having receiving holesfor the link pins,

positioning the at least one pair of outer link plates so that each endregion of a link pin is assigned one of the outer link plates of a pairof outer link plates and the axis of the receiving hole is aligned withthe axis of the associated link pin,

pressing the two outer link plates of a pair of outer link plates in oneoperation onto the end regions of two link pins to produce an outerchain link connected to at least two inner chain links arranged in arow,

riveting the ends of the link pins.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, method variants will be explained in more detail usingdrawings, in which:

FIG. 1 shows a schematic flow diagram relating to joining a single chainin four cycle steps and

FIG. 2 shows a basic sketch of a flow diagram for producing a duplexchain in five cycle steps.

DETAILED DESCRIPTION OF THE INVENTION

In contrast to the most familiar methods in the prior art, according tothe assembly method of the invention, the chain is not built up frombottom to top by being placed on the lower outer link plates. Instead,here a different assembly direction is selected, which has previouslybeen known only in the case of cranked track chains. The hollow pin axesaccordingly run substantially parallel to the supporting or retainingface of the inner chain link. This means that the inner chain link is ontop with the lower narrow sides (or a region thereof) of the inner linkplates or a region of the outer circumference of the hollow pins. Inaddition, the lower narrow sides of the outer link plates may be on top.Also intended to be comprised is an assembly variant in which rollersare also arranged on the hollow pins (in order to produce a rollerchain) and, under certain circumstances, can also be used on top. Thehollow pin axes are principally aligned horizontally. In addition, thelower narrow sides and a plane running through the two horizontal pinaxes are beneficially arranged horizontally. By this means, the innerchain link is accessible from two sides, for which reason the outer linkplates can also be supplied simultaneously from both sides. The layerconstruction hitherto permitted no other assembly sequence, sinceotherwise the link pin had to be pushed completely through a link plate.

Although there is also a method which does not work against a fixedstop, a vertical arrangement of the hollow pin axis was hitherto alwaysselected in this method, for guidance reasons. The fact that hitherto nodeviation has been made from the horizontal arrangement of the linkplates in the case of non-cranked chains probably has something to dowith the greater contact surface for guiding at least the link plates.Because of the fact that these link plates no longer have theseadvantages in the case of cranked chains the on-edge arrangement was theobvious thing in these cases. However, hitherto this did not cause thoseskilled in the art to also perform an on-edge arrangement whenassembling “normal” link-plate chains with inner and outer chain links.In addition, it should also be noted that U.S. Pat. No. 4,027,471 merelyshows an assembly operation and an apparatus which performs completejoining in a single operation.

Although assembly is generally carried out chain link by chain link, itis quite possible for provision to be made for the individual steps tobe carried out in parallel on a plurality of chain links at the sametime.

The construction of U.S. Pat. No. 4,027,471 for the production of thechains is not suitable either for the mass production of conventionaldrive or conveyor chains. Using this construction, only the much slowerproduction of large track chains is possible. The masses to be moved inthis machine would in all probability not permit the high speeds whichare present during normal chain production.

In order that, at least in one direction, no additional precautionsagainst slipping of the inner chain link have to be made, thearrangement of the inner chain link on the supporting or retaining facecan be carried out in such a way that the hollow pin axes are arrangedsubstantially at right angles to the action of the force of gravity.This means that both link plates can be used for support. The action ofsupplying the outer link plates for the outer chain link can be carriedout freely accessibly from both sides, since neither of the outer linkplates has to serve as a horizontal support.

As a rule, it will be simpler if, according to one variant, first of allthe inner chain link is positioned and then the associated link pins aresupplied to be positioned. The inner chain link on top in no way hindersthe subsequent relative insertion of the link pin into the inner chainlink. In the case of specific machine variants, however, it could alsobe advantageous if the link pins are positioned first and then theassociated inner chain link is supplied to be positioned. Because of thefact that the link pin axes are likewise aligned in parallel with thesupporting or retaining face of the inner chain link, these have to beheld clamped in on one side.

Furthermore, the outer link plates of a pair of outer link plates can beprepositioned from both sides relative to the associated inner chainlinks. This method step should be carried out as uniformly as possible,in order that the entire operation can be integrated into one workingcycle. The supplying action has to be concluded at the least only beforethe two outer link plates are pressed on, so that here the cycle of theentire operation may be set very effectively. As a result of pressingthe outer link plates on simultaneously, these two pressing operationstoward each other at the ends of the link pins have only a very slightinfluence. In the case of chain assembly methods mostly used hitherto,one press connection is always ready before the other is produced. Here,it is necessary to ensure that as little influence as possible isexerted by further pressing operations on the press connection finishedfirst.

One method variant beneficially provides for the method steps to becombined into four cycle groups, the steps of one cycle group beingcarried out at the same time by machines. Normally, one cycle groupalways means a to and fro movement of a press tool for assembling thecomponents. The cycle groups are divided up as follows:

the first cycle group comprises the steps of providing at least onecompletely prefabricated inner chain link, positioning the inner chainlink so that the hollow pin axis of the at least one inner chain link isaligned substantially parallel to the supporting or retaining face ofthe inner chain link,

the second cycle group comprises the steps of providing at least onelink pin, positioning the at least one link pin so that the pin axis isarranged coaxially with the hollow pin axis of the associated hollow pinof an inner chain link, inserting the link pin into the hollow pin bymeans of relative displacement of the link pin and of the at least oneinner chain link in relation to one another so that the end regions ofthe link pin project on both sides, the third cycle group comprises thesteps of providing at least one pair of outer link plates having areceiving hole for the link pins, positioning the at least one pair ofouter link plates so that each end region of a link pin is assigned oneof the outer link plates of a pair of outer link plates and the axis ofthe receiving hole is aligned with the axis of the associated link pin,pressing the two outer link plates of a pair of outer link plates in oneoperation onto the end regions of two link pins to produce an outerchain link having at least two inner chain links arranged in a row,

the fourth cycle group comprises the step of riveting the ends of thelink pins.

The chain to be produced is moved forward cycle by cycle or step by stepand these four cycle groups are carried out one after another. Thismeans that after four cycle groups, at least one inner chain link isalways connected to an outer chain link. Purely theoretically, it wouldalso be conceivable to combine the two first cycle groups if the supplyproblem has to be solved quickly.

On account of the fact that the method can be used not only for theassembly of single chains, in a method variant for producing a multiplechain, in particular a duplex chain, additional steps are also provided:

arranging at least two completely prefabricated inner chain links lyingbeside each other so that the hollow pin axes of the inner chain linkslying beside each other are arranged coaxially with each other,

between inner chain links lying beside each other, intermediatelyjoining at least one center link plate having receiving holes for thelink pins, so that the axes of the holes are arranged coaxially with thehollow pin axes. The center link plates can be both subsequently pressedonto the link pin and also seated loosely on the latter. Depending onthe number of tracks of the multiple chain running beside one another, acorresponding number of inner chain links is arranged beside oneanother. The inner chain links are then separated from one another ineach case by a center link plate or two center link plates. Like theouter link plates, in each case a center link plate joins two innerchain links together with the respectively associated link pins.

In this method variant for multiple chains, provision can likewise bemade for the link pins to be positioned first and then for theassociated inner chain links with link plates to be supplied to bepositioned.

In addition, in the production of multiple chains, the method steps arepreferably combined into cycle groups. Here, there are beneficially fivecycle groups, the steps of one cycle group being carried outsimultaneously by machines. The cycle groups are grouped as follows:

the first cycle group comprises the steps of providing at least onecompletely prefabricated inner chain link, positioning the inner chainlink so that the hollow pin axis of the at least one inner chain link isaligned substantially parallel to the supporting face or retaining faceof the inner chain link, arranging at least two completely prefabricatedinner chain links lying beside each other so that the hollow pin axes ofthe inner chain links lying beside each other are aligned coaxially withone another,

the second cycle group comprises the steps of joining at least onecenter link plate having a receiving hole for the link pins betweeninner chain links lying beside each other, so that the hole axes arearranged coaxially with the hollow pin axes,

the third cycle group comprises the steps of providing at least one linkpin, positioning the at least one link pin so that the pin axis isarranged coaxially with the hollow pin axis of the associated hollow pinand the receiving hole of the center link plate, inserting the link pininto the hollow pin and the receiving hole of the center link plate bymeans of relative displacement of the link pin, of the at least oneinner chain link and of the center link plate in relation to oneanother, so that the end regions of the link pin project on both sides,

the fourth cycle group comprises the steps of providing at least onepair of outer link plates having a receiving hole for the link pins,positioning the at least one pair of outer link plates so that each endregion of a link pin is assigned one of the outer link plates of a pairof outer link plates and the axis of the receiving hole is aligned withthe axis of the associated link pin, pressing the two outer link platesof a pair of outer link plates in one operation onto the end regions oftwo link pins to produce an outer chain link connected to at least twoinner chain links arranged in a row,

the fifth cycle group comprises the step of riveting the ends of thelink pins.

Hitherto, in order to construct a duplex chain, eight cycle steps wereneeded if this were constructed with the layer construction, beginningwith the lower outer link plate. This number increased accordingly themore tracks the multiple chain had.

Furthermore, the first and the second cycle group in the production ofmultiple chains can also be carried out in the opposite sequence. If, inthe case of a duplex chain, one begins with the center link plate, thenthe construction is again carried out symmetrically from the inside tothe outside, starting from the center line. Here, too, there is thepossibility of firstly pushing the pin into the receiving hole relativeto the center link plate and then of placing the inner chain links fromboth sides.

In the following text, method variants will be explained in more detailusing drawings, in which:

Illustrated in simplified form in FIG. 1 is an inner chain link 1 which,although it can be produced from one block, preferably comprises twoparallel inner link plates 2 and 3 and hollow pins 4 and 5 connectingthese to each other. The hollow pins 4 and 5 are pressed into holes inthe inner link plates 2 and 3 and hold the inner link plates 2 and 3 ata distance. The hollow pin axes A are aligned horizontally in the firstcycle group of the assembly method, which means that they are arrangedsubstantially at right angles to the action of the force of gravity.However, this also means that FIG. 1 can be viewed as a plan view.

The material used is generally steel with appropriate strength values.Running rollers can also be arranged on the hollow pins 4 and 5 in orderto produce a roller chain.

Because of the alignment of the inner chain link 1, the latter rests onthe lower narrow sides of its inner link plates 2 and 3 or on thecircumferential surfaces of the hollow pins 4 and 5.

Following the cycle group one, two link pins 6 and 7 are positioned sothat the link pin axes are aligned coaxially with the hollow pin axes A.The link pins 6 and 7 are then pushed into the cylindrical openings 8and 9 of the sleeve-like hollow pins 4 and 5. Whether the activemovement is carried out by the link pins 6 and 7 or by the inner chainlinks 1 plays a minor part in the method sequence. The important factoris that a relative movement is carried out between these components.

In the third cycle group, the outer link plates 10 and 11 are suppliedas a pair. The alignment of the outer link plates 10 and 11 is carriedout parallel to the alignment of the inner link plates 2 and 3 butoffset along the chain center axis M, so that the outer link plates 10and 11 are in each case connected to two chain links 1. The outer linkplates 10 and 11 each have two cylindrical receiving holes 12 and 13arranged at a distance from each other, whose hole axis B is alignedcoaxially with the link pin axis and hollow pin axis A. Pressing is thencarried out by means of simultaneously pushing the outer link plates 10and 11 onto the end regions of the link pins 6 and 7. In the process,the outer link plates 10 and 11 are in each case pushed onto two linkpins 6 and 7 of adjacent inner chain links 1. This pushing-on action iscarried out directly to size. For this purpose, a tongs-like movement iscarried out symmetrically in relation to the center axis M, while thelink pins 6 and 7 are centered symmetrically in relation to the chaincenter axis M or are fixed before the outer link plates 10 and 11 arepressed on. In order to carry out such a procedure a device as describedin DE 19836374, for example, is suitable. This permits the centeredfixing of two link pins 6 and 7 at the same time and the subsequentlycentered action of pushing the outer link plates 10 and 11 on from bothsides at the same time.

This means that both outer link plates 10 and 11 carry out a relativemovement in relation to the stationary link pins 6 and 7 and to thestationary main chain axis M.

The pushing-on action is carried out in one operation to size, so thatunnecessary loadings of the press fit are avoided.

In the fourth cycle group, the projecting end regions of the link pins 6and 7 are riveted by means of a riveting operation.

Each of the cycle groups is carried out at one station of a chainassembly device before the chain to be assembled is moved onward by onecycle step.

In the following text, a method variant for the assembly of a multiplechain will be described using FIG. 2. In the practical case, this is aduplex chain. If reference is made to elements which are identical andhave the same effect, the same reference symbols will be used and, tothis end, reference will be made to the preceding description whileavoiding repetition.

In the first cycle group of this assembly method, two inner chain links1 arranged parallel to each other are prepositioned in such a way thattheir hollow pin axes A are aligned with each other and they arearranged at a small distance from each other. Here, too, the inner chainlinks 1 can be constructed or modified as already described above. Thearrangement is made in such a way that the hollow pin axes A arearranged horizontally, which means substantially at right angles to theaction of the force of gravity.

In a second cycle group, two center link plates 14 and 15 are introducedinto the gap 16 between the inner chain links 1. The center link plateshave two cylindrical receiving holes 17 and 18 which are arranged at adistance from each other and whose hole axes are aligned coaxially or inalignment with the hollow pin axes A. The center link plates 14 and 15are arranged along the main center axis M so as to be offset withrespect to the inner chain links 1, so that in each case a center linkplate 14 or 15 is assigned to two inner chain links 1. The center linkplates 14 and 15 are also arranged parallel to the inner link plates 2and 3 of the inner chain links 1.

In a third cycle group, the link pins 6 and 7 are firstly prepositionedsuch that they are in each case aligned coaxially with the associatedhollow pin axes A before they are subsequently pushed into the openings8 and 9 of the hollow pins 4 and 5 and into receiving holes 17 and 18 ofthe two center link plates 14 and 15, so that the end regions of thelink pins 6 and 7 project laterally beyond the inner chain links 1.

In a fourth cycle group, the outer link plates 10 and 11 are suppliedsimultaneously from the side, so that the axes B of their receivingholes 12 and 13 are aligned coaxially with the associated axes A of thelink pins 6 and 7 and the hollow pins 4 and 5. In this case, the outerlink plates are arranged to be offset in exactly the same way as thecenter link plates 14 and 15 in the direction of the main chain centeraxis M. Immediately after being supplied, the outer link plates 10 and11 are pressed onto the end regions of the link pins 6 and 7,symmetrically with respect to the main chain axis M. Here, too, the linkpins 6 and 7 are previously centered or held fixed symmetrically withrespect to the main chain axis M and then the outer link plates 10 and11 are pushed onto the stationary link pins 6 and 7 at the same time.

In the fifth cycle group, the riveting of the end regions of the linkpins 6 and 7 is finally carried out.

Accordingly, by means of five cycle groups, duplex chains and evenmultiple chains with a plurality of tracks can be produced. Here, too,each cycle group again means moving the chain forward by one cycle step,while the subsidiary steps are carried out within one cycle group.

In particular in the case of producing the multiple chain, the cyclegroups can also be carried out in a different sequence. There is, forexample, the possibility of supplying and arranging the center linkplates 14 and 15 first, then pushing or pressing the link pin 6 and 7into the center link plate 14 and 15 and then pushing the inner chainlinks 1 on from the outside. The cycle groups four and five then proceedin the accustomed sequence again. However, this different sequence doesnot increase the total number of cycle groups to be carried out. In thecase of a layer construction, in the case of each additional track of amultiple chain, some assembly cycle groups will again be added, since ineach case after a center link plate has been joined, a layer of innerchain links again has to be put in place first.

As opposed to the production of a cranked track chain, during eachoperation uniform symmetrical forces are always applied during thepressing-on action since in each case the same diameters and press-fitrelationships are concerned. In the case of a track chain, on the otherhand, in each case a solid pin and a hollow pin has to be pressedsimultaneously, with completely different force relationships.

The invention therefore leads to a considerable reduction in the cyclegroups in a cycled production method for producing “simple” link platechains comprising inner chain links and outer chain links.

What is claimed is:
 1. A chain assembly method for joining a linkplatechain having alternating outer and inner chain links, said assemblymethod comprising the following steps: providing two completelyprefabricated inner chain links, positioning the two inner chain linksin a row and so that a hollow pin axis of each of the two inner chainlinks is aligned substantially parallel to a hollow pin axis of theother and to a supporting or retaining face of the inner chain link (1)links, providing two link pins, positioning the two link pins so that anaxis of each link pin is arranged coaxially with a hollow pin axis ofone of the two inner chain links, inserting the link pins into thehollow pin axes by relative displacement of the link pins and of the twoinner chain links in relation to each other so that end regions of linkpins project from both sides of the two inner chain links, providing atleast one pair of outer link plates having receiving holes for the linkpins, positioning the outer link plates so that each end region of thelink pins is assigned one of the receiving holes of the outer linkplates of the pair of outer link plates and an axis of the receivingholes is aligned with the axis of the associated link pin, pressing thetwo outer link plates of the pair of outer link plates in one operationonto the end regions of the two link pins to produce an outer chain linkconnected to the two inner chain links arranged in a row, and rivetingthe ends of the link pins.
 2. The method of claim 1, in which thearrangement of the inner chain links on the supporting or retaining faceis carried out in such a way that the hollow pin axes are arrangedsubstantially at right angles to the action of the force of gravity. 3.The method of claim 1 or 2, in which the inner chain links arepositioned first and then the associated link pins are supplied to bepositioned.
 4. The method of claim 1 or 2, in which the link pins arepositioned first and then the associated inner chain links are suppliedto be positioned.
 5. The method of claim 1 wherein the outer link platesof the pair of outer link plates are positioned simultaneously from bothsides relative to the associated inner chain links.
 6. The method ofclaim 1 wherein the action of pressing the two outer link plates of thepair of outer link plates in one operation is carried out symmetricallyin relation to the link pins previously fixed symmetrically with respectto a chain center line.
 7. The method of claim 1 wherein the methodsteps are combined into four cycle groups, the steps of one cycle groupbeing carried out simultaneously by machines, the first cycle grouphaving the steps: providing the two inner chain links positioning theinner chain links in a row so that a hollow pin axis of each inner chainlink is aligned substantially parallel to the hollow pin axes of theother and to a supporting or retaining face of the inner chain links,the second cycle group having the steps: providing the two pins,positioning the two pins so that an axis of each pin is arrangedcoaxially with a hollow pin axis of an associated inner chain link,inserting the link pins into the hollow pin axes by relativedisplacement of the link pins and of the two inner chain links inrelation to one another so that end regions of the link pins projectfrom both sides of the inner chain links, the third cycle group havingthe steps: providing at least one pair of outer link plates havingreceiving holes for the link pins, positioning the at least one pair ofouter link plates so that each end region of a link pin is assigned areceiving hole of an outer link plate of the pair of outer link platesand an axis of a receiving hole is aligned with the axis of theassociated link pin, pressing the two outer link plates of the pair ofouter link plates in one operation onto the end regions of the two linkpins to produce an outer chain link connected to the two inner chainlinks arranged in a row, and the fourth cycle group having the step:riveting the ends of the link pins.
 8. The method of claim 1 forproducing a multiple chain, which additionally comprises the followingsteps: arranging two sets of inner chain links in a row, each setcomprising at least two completely prefabricated inner chain links lyingbeside each other so that the hollow pin axes thereof are arrangedcoaxially with one another, joining at least one center link platehaving receiving holes for the link pins between the two sets of innerchain links so that receiving hole axes of the center link plate arearranged coaxially with the hollow pin axes of the inner chain links. 9.The method of claim 8, wherein the link pins are positioned first andthen the associated inner chain links and center link plate are suppliedto be positioned.
 10. The method of claim 8 wherein the method steps arecombined into five cycle groups, the steps of one cycle group beingcarried out substantially simultaneously by machines, the first cyclegroup having the steps: providing the two sets of inner chain links,positioning the two sets of inner chain links in a row so that thehollow pin axes of the links are aligned substantially parallel to eachother and a supporting or retaining face of the inner chain links, thetwo inner chain links of each set lying beside each other so that thehollow pin axes thereof are arranged coaxially with one another, thesecond cycle group having the steps: joining at least one center linkplate having receiving holes for the link pins between the two sets ofinner chain links so that receiving hole axes of the center link plateare arranged coaxially with the hollow pin axes of the inner chainlinks, the third cycle group having the steps: providing the two linkpins, positioning the two link pins so that an axis of each pin isarranged coaxially with a hollow pin axis of an associated of an innerchain link, inserting the link pins into the hollow pin axes and thereceiving holes of the center link plate by relative displacement of thelink pins and of the inner chain links and center link plate in relationto each other so that end regions of the link pins project from bothsides of the two sets of inner chain links, the fourth cycle grouphaving the steps: providing at least one pair of outer link plateshaving receiving holes for the link pins, positioning the at least onepair of outer link plates so that each end region of a link pin isassigned a receiving hole of an outer link plate of the pair of outerlink plates and an axis of a receiving hole is aligned with the axis ofthe associated link pin, pressing the two outer link plates of the pairof outer link plates in one operation onto the end regions of the twolink pins to produce an outer chain link connected to at least two setsof inner chain links arranged in a row with the center link platebetween them, and the fifth cycle group having the step: riveting theends of the link pins.
 11. The method of claim 10, wherein the first andsecond cycle groups are carried out in a different sequence.
 12. Themethod of claim 11, wherein the link pins are pushed into the centerlink plate before the first cycle group is carried out.